Error while installing on SAR system

[hh85v2]

Environment:
Umidigi Bison, Android 10.0, system as root, no separate 'system' partition.

Problem:
Installation process ends with "Error occured while mounting /system" message.

Reason:
No wonder, since there's no such partition:
# mount -o remount /system
mount: '/system' not in /proc/mounts

Proposed solutions:

1.Add to 'update-binary' the additional check for the symlink '/dev/block/by-name/system' existence. If found, we can proceed to mounting-remounting procedure as usual. Else just skip it, cause /system directory with all its content is indeed already in it's place.
2. Alternatively check '/dev/block/by-name/super', which can be more precise. Its existence means we have SAR. That's partition, where /system and some other essential directories are placed. Obviously, the further logic must be inverted.

One more thing. Did not understand, if the script considers installing the service both systemlessly and to the real system. I guess it does. But in case of SAR the later is completely senseless, because /system can't be writable by design. Thus, if it was detected and Magisk wasn't, we have to exit with corresponding message.

P.S. Thanks for your work. Used this module with my previous phone and sold it after 2 years with 94% (!) of its battery capacity.